1. Field of the Invention
The present invention relates to the technology field of power converters, and more particularly to a switch power converter and a frequency response characteristic testing and adjusting method for the switch power converter.
2. Description of the Prior Art
Power converters, for example, the switching power converters, are broadly applied in the power systems of all kinds of industrial electrical equipment. For keeping the accuracy and stability of the power system, engineers need to accomplish the small-signal model analysis and the frequency response characteristic test of the power converter in the power system, so as to modulate and/or compensate the frequency response characteristic of the power converter for making the whole power system be able to operate reliably under a stable working range.
Please refer to FIG. 1, which illustrate a schematic connection diagram of a frequency response analyzer and a power system. As FIG. 1 shows, the frequency response analyzer 13′ is connected to a power converter 11′ and a controller 12′ of a power system for testing the frequency response characteristic of the power converter 11′. After the frequency response analyzer 13′ outputs a disturbance signal CH1′ to the controller 12′, the controller 12′ outputs a control signal x′ including the disturbance signal CH1′ to the power converter 11′, and then the power converter 11′ outputs a stable output signal y′ correspondingly.
Because CH2′ is a voltage division signal of the stable output signal y′, the frequency response characteristic of y/x can be determined by way of inputting the disturbance signal CH1′ with a specific input range and then respectively measuring each of the control signals x′ and the stable output signals y′ under each of input frequencies. Therefore, the amplitude-frequency characteristic of the power converter 11′ represented by the amplitude-ratio variation depending upon the frequency change of the stable output signals y′ and the control signals x′ can be measured; moreover, the phase-frequency characteristic of the power converter 11′ represented by the phase angle difference depending upon the frequency change of the stable output signals y′ and the control signals x′ can also be obtained.
For a complex-structure power converter which is hard to be carried out the small-signal model analysis thereof, the aforesaid frequency response analyzer is very useful for testing the frequency response characteristic of the complex-structure power converter. However, when output power of the power system reaches to MW level, the disturbance signal injected into the power system by the frequency response analyzer would be ignored opposite to the MW-level output power, such that the frequency response analyzer cannot accomplish the frequency response characteristic test of the power converter in the power system.
Moreover, if there are multiple power converters paralleled in the power system, the characteristic of the power system may have some variation because the single stable power converter does not be stable anymore after being paralleled with other power converters. In addition, the stable-working power system may become unstable after a new load (or electrical grid) differing from the originally-connected (or electrical grid) load is connected to the power system; meanwhile, the frequency response analyzer is used again for testing the frequency response characteristic of the power converter in the power system. However, the use of the frequency response analyzer becomes more and more inconvenient due to the limitations of the disposing space of the power system and other resources.
Accordingly, in view of the conventionally used frequency response characteristic testing and adjusting way still including drawbacks and shortcomings, the inventor of the present application has made great efforts to make inventive research thereon and eventually provided a switch power converter and a frequency response characteristic testing and adjusting method for the same.